Electrical plugs, such as those conforming to the National Electrical Manufacturers Association (NEMA) 5-15P or NEMA 6-20P standards, are used to connect electrical devices with electrical sockets, such as those conforming to NEMA 5-15S or NEMA 6-20S standards. There are several issues that may arise in the use of these plug/socket combinations. First, as shown in FIG. 1, an operator's fingers 1 may inadvertently contact the conductive pins 2 of the plug 3 as the plug 3 is inserted into an electrical outlet socket (not shown) surrounded by a flat wall plate 4, posing a risk of electric shock to the operator. Second, as shown in FIG. 2A, an operator 1 may attempt to remove the plug 3 from the socket by grasping the electrical cord 5 attached to the plug 3 and pulling on the cord 5 rather than properly grasping the plug 3. As shown in FIG. 2B, this may cause the plug 3 to rotate in the socket and cause damage to the pins 2 that result in increased electrical resistance and increased pin temperatures in use or could cause pin failure. Similar rotation of the plug 3 in the socket may also be caused by an electrical device 6, such as an electric vehicle battery charger, also known as electric vehicle service equipment (EVSE), hanging from an outlet 7 where the socket 8 is oriented such that the cord exits the top of the plug and then curves outwardly to extend to the EVSE as shown in FIG. 3.
Although this problem of plug rotation may more acutely affect angled plugs 3 having a 90 degree cord 5 to pin 2 relationship as in the plugs shown in FIGS. 2A and 2B, a straight plug 9 having a 180 degree relationship between the pins 2 and the cord 5 as shown in FIG. 4 may also experience rotation in the socket that could damage the plug pins if the cord or plug is pulled or yanked in an upward or downward direction.
Therefore, a needs exists to inhibit damage to plug pins caused by rotation of the plug pins in the socket.
The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions.